Am 27.01.2014 um 10:53 schrieb Flavien Lambert <petit.lepton@gmail.com>:

Dear all,
I would like to use the light version of the Ubuntu font both for text and for text in math environment. The list of fonts is the following

mtxrun --script fonts --list --all  | grep ubuntu
ubuntu                               ubuntu                            /home/flavien/.fonts/Ubuntu-R.ttf
ubuntubold                           ubuntubold                        /home/flavien/.fonts/Ubuntu-B.ttf
ubuntubolditalic                     ubuntubolditalic                  /home/flavien/.fonts/Ubuntu-BI.ttf
ubuntucondensed                      ubuntucondensedregular            /home/flavien/.fonts/Ubuntu-C.ttf
ubuntucondensednormal                ubuntucondensedregular            /home/flavien/.fonts/Ubuntu-C.ttf
ubuntucondensedregular               ubuntucondensedregular            /home/flavien/.fonts/Ubuntu-C.ttf
ubuntuitalic                         ubuntuitalic                      /home/flavien/.fonts/Ubuntu-RI.ttf
ubuntulight                          ubuntulight                       /home/flavien/.fonts/Ubuntu-L.ttf
ubuntulightitalic                    ubuntulightitalic                 /home/flavien/.fonts/Ubuntu-LI.ttf
ubuntumedium                         ubuntumedium                      /home/flavien/.fonts/Ubuntu-M.ttf
ubuntumediumitalic                   ubuntumediumitalic                /home/flavien/.fonts/Ubuntu-MI.ttf
ubuntumono                           ubuntumonoregular                 /home/flavien/.fonts/UbuntuMono-R.ttf
ubuntumonobold                       ubuntumonobold                    /home/flavien/.fonts/UbuntuMono-B.ttf
ubuntumonobolditalic                 ubuntumonobolditalic              /home/flavien/.fonts/UbuntuMono-BI.ttf
ubuntumonoitalic                     ubuntumonoitalic                  /home/flavien/.fonts/UbuntuMono-RI.ttf
ubuntumononormal                     ubuntumonoregular                 /home/flavien/.fonts/UbuntuMono-R.ttf
ubuntumonoregular                    ubuntumonoregular                 /home/flavien/.fonts/UbuntuMono-R.ttf
ubuntunormal                         ubuntu                            /home/flavien/.fonts/Ubuntu-R.ttf
ubunturegular                        ubuntulight                       /home/flavien/.fonts/Ubuntu-L.ttf

I tried a script that I used before for Maven pro through,

\definefontfeature[default][default][script=latin]
\definefontfamily[mainface][sans][ubuntulight]
\definefallbackfamily [mainface] [math] [ubuntulight] [math:lowercaseitalic] [force=yes]
\definefallbackfamily [mainface] [math] [ubuntulight] [math:digitsnormal]    [force=yes]
\definefontfamily     [mainface] [math] [TeX Gyre Pagella Math]
\definebodyfontenvironment [11pt][a=12pt,b=14.4pt,c=17.3pt,d=32pt,interlinespace=13pt]
\setupbodyfont[mainface,11pt]

but it does not work (it is ok if I use ubuntu instead of ubuntulight).

This doesn’t work because the name of the family is still “Ubuntu” and not “Ubuntu Light”,
(you can see in the attached image how the font is listed in my font manager) to use the light
alternative of the font add “tf=style:light” to \definefontfamily and \definefallbackfamily.

\definefontfamily [mainface] [sans] [Ubuntu] [tf=style:light]

\definefallbackfamily [mainface] [math] [Ubuntu] [preset=math:lowercaseitalic,tf=style:light]
\definefallbackfamily [mainface] [math] [Ubuntu] [preset=math:digitsnormal,tf=style:light]
\definefontfamily     [mainface] [math] [TeX Gyre Pagella Math]

\setupbodyfont[mainface,11pt]

\starttext
123 \math{123}
\stoptext

Wolfgang